1. Field of the Invention
The present disclosure generally relates to remote control systems and, particularly but not exclusively, it relates to systems operating by transmitting infrared radiation (known as “Infrared Remote Control System”).
2. Description of the Related Art
Remote control systems are used for commanding various types of apparatus such as, for example, televisions or gate automations. These remote control systems are known to comprise a transmitter provided, typically, with one or more buttons with which the user selects the command to be transmitted to a receiving apparatus connected to the appliance to be commanded.
Following the action on the button, inside the transmitter a modulated digital signal is generated that transports the digital information to be transmitted which, in turn, is used to pilot a source of light, such as an infrared led which emits radiation towards the receiver. This modulated signal is, generally, of a pulse type in which the position and/or width of the impulse codify the digital information. For example, the best known of the codings used for generating the digital signal is the RC5 coding, proposed by Sony, and according to which the symbol 0 and the symbol 1 are differentiated by a different position of the pulse (that is of the high logic level) within the overall duration interval of the symbol.
It has been observed that the impulse generation modality, and thus the modulated signal generation modality, have particular importance for the efficiency and costs of production of the transmitter.
Transmitters for control systems are known in which the modulated signal is entirely generated by software, by means of suitable algorithms performed by a microcontroller.
This generation by software does not appear satisfactory in that it requires excessively high calculation times in relation to the relative simplicity of the codes of the modulated signal and, moreover, it translates into a software overload which, as a whole, degrades the performance of any microcontroller not dedicated to the abovementioned object.
Different solutions are also known, in which the modulated signal is generated by a complex network of discrete circuit elements that have high costs of production and the disadvantage of not permitting a reconfiguration in time in order to respond, for example to an optional need to use different types of coding.